Slip-switch timing mechanism



March 1932- G. H. WHITTINGHAM SLIP SWITCH TIMING MECHANISM Filed Aug 13,1951 2 $heets-Sheet March 29, 1932. G. H. WHITTINGHAM SLIP SWITCH TIMINGMECHANISM Filed Aug 15, 1931 2 Sheets-Sheet Patented ll lar. 29, 1932GEORGE E. WI-IZT'IINGHAM, F BALTIMORE, MARYLAND, ASSIGNOR T0 MONITORCON- TROLLER COMPANY, 0F BALTIMOEE, MARYLAIWD, A'COR-PORATIOII 0FMARYLAND SLIP-SWITCH TIMING EIECHANISM Application filed August 13,1931. Serial No. 556,895.

This invention relates to mechanism for controlling electric circuits byopening or closing the same in predetermined times and predeterminedorder after the performance of P an initial operation which starts themechanism into operation, and for resetting the circuit-controllingmembers in their initial positions so that the operations may berepeated.

This application is a continuation in part 510 of my application filedJuly 7, 1930, Serial Number 466,308, and embodies structural improvements upon the invention described in my reissue application SerialNumber 550,- 806, filed July 14, 1931.

In the aforesaid reissue application and in the present application, themechanism comprises a shaft which is rotated at a very slow and constantspeed; a series of switch members mounted upon a stationary support ad-.20 jacent the shaft, a plurality of cricuit-controlling members looselyjournaled on the shaft and adapted to engage the stationary members, thecircuit-controlling members being biased away from the stationarymembers and adapted to rock freely on the shaft into engagement with afixed stop; friction devices of conducting material rotatable with theshaft and arranged on opposite sides of the circuit-controlling members,and means for clamping said devices against the circuitcontrollingmembers to cause the latter to move with the shaft in the direction toengage the stationary members. Each circuit-controlling member has anarm which is adjustable toward and from the opposing stationary member,to vary the time of engagement of the arm with the latter member. Theshaft rotates very slowly and at aknown speed, so that by adjusting thearm on the circuit-controlling member the time of engagement may beaccurately pro-set. As each circuit-controlling member cngages astationary member the former member stops, while the frictiondeviceswhich engage it continue in operation, holding the former memberin engagement with the latter. When it is desired to reset the switches,the friction devices are released from the circuit-controlling membersand the latter then rock on the shaft to their initial positions againsta fixed stop.

The present invention relates more particularly to the moun ing of thefriction devices and the circuit-controlling members, whereby theengagement and disen agement ofthe friction devices with thecircuit-controlling members is improved.

In the accompanying drawings, *ig. 1 is a front elevation of the mecha-1 1g. 2 is a front elevation of the apparatus, the shaft which operatesthe circuit-controlling mechanism being shown in longitudinal section;

3 is a top plan view with the motor removed;

F a is a section on the line 4- l of Fig. 2;

F 5 is a similar section showing the apparatus as used to open circuits;

6 is a perspective view of one ofthe friction-block carriers;

Fig. 7 is a side elevation of one of the movable switch members, itscontact arm being removed;

Fig. 8 is a side elevation of a modified form of friction-block carrier,and,

Fig. 9 is an edge view of the same, looking from right to left in Fig.7.

Referring to Figures 1 to 6 of the drawins, 1 indicates a suitable baseof insulating m terial to which are secured forwardly projecting metalbars 2 and 3, spaced apart from one another and forming supports for theworking parts of the apparatus. A tubular t extends horizontally throughthese of the apparatus shaft bars and is journaled therein, and uponthis shaft is mounted a worm wheel 5, which is geared to a smallelectricmotor 6 by reduction gearing whicn causes the worm wheel and shaft l toturn at a very low speed when the motor is in operation. The motor isone which operates at constant speed.

A number of disks a, 01-, a and a which constitute carriers for blocksof electrically conductive material '7, preferably carbongraphitecomposition, are mounted upon the shaft so as to turn with it. Thecarrier a is fir dly secured to the shaft by a set screw 8. This carrierhas two diametrically opposite sockets 8 in which are fittedthe twocylindrical blocks 7 of carbon-graphite composition.

1 supported by a insulating base 1. 'The edge of the strip 18,

The carriers a, a and a are alike, each comprising a disk 9 having twodiametrically opposite cylindrical sleeves 9 which extend parallel withthe axis of the disk and consti tute holders for the cylindricalcarbongraphite blocks 7. These blocks fit closely within the holders,but are freely movable longitudinally therein and project beyond theirends. Each of these carriers has a hub 9 which fits on to the shaft 4,and a tongue 9 on the hub extends into a keyway 10 in the shaft, so thatthe carrier may be driven by the shaft. The hub projects atone side ofthe disk for a considerable distance beyond the ends of the holders onthat side, this part 9 of the-hub forming a bearing for acircuitcontrolling member hereinafter described. The carriers a, a ,'aare assembled on the hollow shaft 4 by sliding their hubs over the lefthand end of the shaft successively and then applying the nut 46 to saidshaft which clamps the hubs together andagainst the hub of the carriera.

. 'Between the carbon graphite blocks in the series of carriers arearranged circuit-com trolling members Z), Z), and 5 each membercomprising a metal plate 11 having a central opening 12 through which ahub of one of the carriers is extended. The circuit-controlling membersfit closely around the hubs but are freely rotatable thereon. The platesare in the form of disks which, for about onehalf of theircircumferential lengths, project radially beyond the peripheries of thecarriers, and the projecting portion of each plate has a flange 13 whichprojects at opposite sides of the plate. This flange, on each plate,forms a support and guide for an adjustable arm. A U-shaped clamp oryoke 14 fits around the flange of the member I) and an arm 15 has ashort right-angled portion m, which is clamped against the periphery ofthe flange by a set screw 16 at the center of the clamp or yoke. The arm15, which, in Figs. 1 to 4., is a contact member, extends in anapproximately radial direction from the flange and is adapted to engagea stationary switch member a, which is mounted upon the switchboard.Similar arms 15 and 15 are adjustably secured to the flanges of themembers 7) and b by clamps 14*, 149, respectively, and these arms 15 and15 are adapted to engagb stationary switch members 0 and respectively. Aweight 17 projects radially from the member I) at one end of its flange,and similarly arranged weights 17 and 17 project from the members I) andI). These weights tend to rock the plates to which they 'areattached soas to hold the arms out of engagement with the stationaryswitch members,and normally a strip of insulating material 18 which is bracket 19connected to the these weights rest against 1 disk 21 to bear againstthe blocks in the car- 7 rier a and the blocks in the several carriers,which are movable endwise in the sleeves or holders, will be clampedagainst the circuitcontrolling members 5, b and IF. A magnet (Z issuspended beneath the supporting bars 2 and 3 by an iron plate 22, whichis secured to said bars, and has a downwardly turned part 22 in which anarmature 23 is pivotally mounted.v This armature has an arm 24' whichprojects upwardly and has an opening through which the right hand endportion of the shaft extends. The shaft 20 has a shoulder 20?) and whenthe magnet is de-energized and its armature is away from its pole-piece,7 against the shoulder and holds the rod in position to release thefriction-blocks, as shown in Figs. 1 and 3. normally held in thisposition by a spring 25 which is coiled upon a stud 26, the latterprojecting horizontally from the arm 22 on the support 22 through anopening in the arm 24. The arm 24 constitutes a lever for moving theshaft 20. On this lever, midway between the shaft 20 and the spring 25,a projection 27 is provided and this forms a ful-V cruin for anotherlever 28, the lower end of whicn is interposed between the spring 25 andthe lever 2d. The upper end of the levr 28 has an opening through whichthe shaft2Q extends and this end of the lever bears against a washer 29which is held in place by a cotter pin 30, passing through the shaft 20.

When the armature 23 is lifted by the magnet, the lever 24 swings awayfrom the shoulder 20", and pressure is applied to the central part ofthe lever 28 at the fulcrum 27. As the spring 25 bears against the lowerend of the lever 28, the upper end of said lever applies a yieldingpressure to the rod 20, tending to force it to the right to clamp thefriction-blocks a gainst the plates of the circuitcontrolling members.hen the armature 23 drops, the lever 2A swings to the left, releasingthe pressure at the center of the lever 28,

and the lever 2%, bearing against the shoulder H 21, moves the rod 20 tothe left, releasing the pressure of; the friction-blocks against theplates of the circuit-controlling members.

A conductor 31- is shown connected to the supporting bar 3 and all ofthe movable parts of the apparatus are electrically connected to thissupport and wire 31. Conductors 33 and 34- are shown connected to theswitch The armature is the arm 2s presses the washer ios members 0, 0,and '0 respectively. The coil of the magnet may be connected to thecurrent source in any desired way, according to the use which is to bemade of the apparatus.

The shaft at turns in the clockwise direction when viewed from its righthand end, while the weights on the circuit-controlling members tend torock said members on the shaft away from the stationary switch members.Normally, the circuit-controlling members are held out of engagementwith the station ary switch members by the weights on the former, whichrests against the stop 18. The motor may run constantly, or it may beswitched into and out of circuit, as desired, according to the purposefor which the apparatus used. The arms on the circuit-controllingmembers will be set at any desired distance from the stationary switchmembers according to the delay desired in closing the circuits. Assumingthe motor to be running and the arms to be set as shown in Figs. 1, 3and 4, if the magnet (Z is energized, it will attract its armature 23and the lever 24, connected to the armature, will press the lever 28 tothe right and tnis latter lever will move the rod 20' in the directionto draw the metal disk against the adjacent friction blocks in carrier aand causes the members 6, 7) and FF to be clamped between the frictionblocks in carriers a, a, a and a As the carriers slowly rotate, the arms15, 15 and 15" will engage the stationary switch members 0, 0' and c resa-ec'tively, in succession. As each arm engages a stationary member themetal plate to which the arm is connected stops while the frictionblocks on either side of the plate conti us to rotate.

When it is desired to reset the switches the circuit of the magnet (Z isbroken and the armature of the magnet drops, causing the lever 24 to bemoved by the spring against he shoulder 20 on the rod 20, and the rod isthereby moved to the left. When the rod 20 is moved to the left, thepressure of the clamping disk 21 against the frictionblocks and platesis relieved. When this occurs, the weights on the circuit-controllingmembers immediately rock said members about the shaft until the weightson said members engage the stop 18. The arms on said memhere are thusreturned to their original preset positions.

The number of friction devices and switch members mounted on the shaftmay be varied, as also the speed of the shaft. For some special purposesthe gearing will be such that the shaft will turn very slowly, sayonehalf revolution in ten minutes. The arms on the circuit-controllingmembers may be se. to close the switches at exact times, as forinstance, ten seconds for one switch, five minutes for another and twominutes for another, and as soon as the friction devices are unclampedfrom the circuit-controlling members, the latter immediately return totheir initial positions so that the operation may be repeated.

As the hubs of the carriers are keyed to the shaft and clamped tightlytogether, the carriers are not movable upon the shaft, but the frictionblocks are movable longitudinally in their holders and the plates of themovable contact members are laterally movable on'the carrier hubs, sothat these plates are clamped by pressure transmitted through the blocksand not through the carriers.

As the friction-blocks, of carbon-graphite composition, are electricallyconductive and mounted in metal carriers upon a metal shaft which isconnected through its bearings to the current source, good electricalcontact is made through the friction-blocks to the circuit-controllingmembers when they are clamped between the friction disks.

In Figs. 1 to 4; the stationary switch members are shown conventionallyas metal posts which the arms on the circuit-controlling membersdirectly engage to close circuits, which circuits are broken when saidmembers are released from the friction devices. The mechanism is used toactuate normally closed switches to open circuits, as illustrated inFig. 5, and for some uses some of the switches may be normally closedand others normally open, or they may be all normally closed, ornormally open. In Fig. 5, l have shown, for the purpose of illustration,a stationary normally closed switch 0 comprising a switch lever 42centrally pivoted on metal post 43 and having one end normally heldagainst a metal post 44 by a spring 45. These posts are terminals of acircuit 46 to be controlled. The opposite ends of the lever is showncovered by a piece of insulating material 47 which the arm 15 of thecircuit-controller b is adapted to engage when the mechanism isoperated, and it will be evident that as the circuit-controller advancesvith the shaft the switch member 42 will be rocked by the arm l5 againsta stop 46 and the circuit will be opened. When the friction devices arereleased and the circuit-controller drops back to normal position, thespring 45 will rock the switch arm to its normal closed position. Thestationary switches may be of the push button type and normally open ornormally closed, as desired. lVhen such are used the arms on thecircuit-controllers serve merely as tappets to actuate the stationaryswitches, and not as switch members.

While I have shown, for the purpose of illustration, only threecircuit-controlling members operated from a common shaft. it will beobvious that the number of such members may be increased as desired,according to the number of circuits to be controlled, by providing alonge shaft and additional friction devices. The mechanism is usedmainly for controlling electric motors where the motor is required tooperate a'machi'ne at different speeds, or for different given periods,and to repeat these operations. The

motor is controlled directly by contactors' and the switch mechanism ofthe present invention controls the circuits of the contactors.

In Figs. 8 and 9, I have shown a modified form of carrier which may besubstituted for those shown in the previously described figures. InFigs. 8, 9, the contactor comprises an angular metal plate 35, having ahub 36, adapted to fit on to the shaft 4. At opposite edges of the plateand in diametrically opposite positions, studs 37 project in the planeof. the plate and at right angles to said edges, and upon these studsare pivoted short pieces of square tubing 38 which are about as long asthe plate and which lie parallel with the aforesaid edges. The free endsof these tubes are formed with longitudinal slots 39, and blocks ofcarbon-graphite composition 40 fit within these slots and are pivotallymounted upon pins 41 which extend through the walls of the slots andthrough the centers of the carbon-graphite blocks. These blocks projectlaterally beyond the sides of the tubes, as shown in Fig. 9, and areadapted to engage the circuit-controlling members when the carriers aremounted upon the shaft 4:.

This carrier rotates in the direction to drag the carbon-graphite blocksaround, which direction is indicated by the arrow in Fig. 8. It will beevident that as the tubes may swing around the pivots 37 and the blocksmay swing to a limited extent around the pivots 41, the blocks can movewhen the clamping disk is moved to clamp or release the switch memberswhile the plates, which constitute the bodies of'the carriers, will berigid with the shaft under all conditions.

lVhat I claim is:

1. An electric slip-switch mechanism comprising a shaft and means forrotating the same, a switch member adjacent the shaft, acircuit-controlling member rotatable about the shaft and also movablelongitudinally thereof, carriers secured to the shaft on opposite sidesof the latter member, frictionblocks mounted in said carriers, theblocks in one of said carriers being movable toward and from theopposing carrier, and means for applying pressure to said latter blocksto cause the circuit-controlling member to be clamped between the blocksof the opposing carriers.

2. An electric slip-switch mechanism com prising a shaft and means forrotatingthe same, a plurality of switch membersadjacent the shaft, aplurality of circuit-controlling members rotatable about andmovablelongitudinally of the shaft and biased away from said switch members,friction-block carriers at opposite sides of the severalcircuit-controlling members, sa1d carrlers fixed to the shaft,friction-blocks mounted in sa1d carriers and movable longitudinally ofthe shaft, and means for clamping said blocks against said movablemembers to cause the latter to rotate with the shaft into engagementwith said switch members.

3. An electric slip-switch mechanism comprising a shaft and means forrotating the same, a plurality of switch members adjacent the shaft, a.plurality of circuit-controlling members, the latter rotatable about andmovable longitudinally of the shaft and biased away from said switchmembers, frictionblock carriers at opposite sides of the severalcircuit-controlling members, said carriers fixed to the shaft,friction-blocks of elec trically conductive material mounted in saidcarriers and movable longitudinally of the shaft, and means for clampingsaid blocks against said circuit-controlling members to cause the latterto rotate with the shaft into engagement with said switch members.

4. An electric slip-switch mechanism comprising a shaft and meansfor-rotating the same,'a plurality of switch members adjacent the shaft,a plurality of circuit-controlling members, the latter rotatable aboutand movable longitudinally of the shaft and biased away from said switchmembers, friction-block carriers atopposite sides of the severalcircuit-controlling members, said carriers fixed to the shaft,friction-blocks of electrically conductive material mounted in thecarriers in alinement with one another and movable longitudinally of theshaft, and means for clamping said blocks against saidcircuit-controlling members to cause the.

latter to rotate with the shaft into engagement with said switchmembers.

An electric slip-switch mechanism comprising a shaft and means forrotating the same, a plurality of switch members adjacent the shaft, aplurality of circuit-controlling members, each of the latter comprisinga disk rotatable about and movable longitudinally of the shaft,friction-block-carriers at opposite sides of the several disks, saidcarriers fixed to the shaft, aplurality of spaced frictionblocks mountedin each carrier, said blocks being movable longitudinally of the shaftand the corresponding blocks in the several carriers being in alinement,and means for clamping said blocks against-said disks and for unclampingthe same.

6. An electric slip-switch mechanism comprising a shaft and means forrotating the same, a plurality of switch members adjacent the shaft, aplurality of circuit-controlling members, each of the latter comprisinga disk rotatable about and movable longitudinally of thesliafhfriction-block carriers at. oppo-' site sides of the severaldisks, each carrier comprlsinga plate secured to theshaft,friction-blocks mounted in each carrier at opposite sides ofthe shaft,said blocks being movable longitudinally of the shaft, and means forclamping said blocks against said disks and for unclamping the same.

7. An electric slip-switch mechanism comprising a shaft and means forrotating the same, a plurality of switch members adjacent the shaft, aplurality of circuit-controlling members, the latter each comprising adisk rotatable about and movable longitudinally of the shaft,friction-block carriers at opposite sides of the severalcircuit-controlling members, each carrier comprising a plate secured tothe shaft and having diametrically opposite sleeves extending parallelWith the shaft, friction-blocks movable longitudinally in said sleevesand projecting beyond the same, and means for clamping said blocksagainst said disks and for unclamping the same.

8. An electric slip-switch mechanism comprising a shaft and means forrotating the same, a plurality of frictionblock carriers each comprisinga plate having a hub secured to said shaft, friction-blocks carried bysaid plates and movable longitudinally of the shaft, a plurality ofcircuit-controlling members, each member journaled on one of said hubsbetween two of said plates, and means for clamping said blocks againstsaid members and for unclamping the same.

9. In an electric slip-switch mechanism of the class described, afriction-block carrier comprising a flat member having means forsecuring it centrally to a shaft and having arms pivotally connected toits edges at diametrically opposite points and adapted to swingtransversely of the plane of said memher, and friction-blocks mounted inthe free ends of said arms and projecting beyond their sides.

10. In an electric slip-switch mechanism of the class described, afriction-block carrier comprising a flat member having means forsecuring it cent-rally to a shaft and having arms pivotally connected toits edges at diametrically opposite points and adapted to swingtransversely of the plane of said memher, and friction-blocks pivotallymounted in the free ends of said arms and projecting beyond their sides.

In testimony whereof I afiix my signature.

GEORGE H. WHITTINGHAM.

